Conductor bar for a stator winding of an electric machine

Abstract

The stator winding of an electrical machine comprises conductor elements which are spaced apart from one another, are electrically insulated from one another and are surrounded over their entire length by common main insulation. The cavities, which are caused by the arrangement on both bar narrow sides of the conductor elements and the main insulation, are filled with an electrically semiconductive compound which, for its part, is covered by an electrically semiconductive strip. In order to provide a smooth bar surface, the electrically semiconductive strip is composed of a fiber-reinforced plastic, which has incisions on alternate sides of the narrow sides of the conductor bar oriented transversely with respect to the bar's longitudinal direction; these incisions are deeper than half the strip width and have a cut width which is on the order of magnitude of the strip thickness.

What is claimed as new and desired to be secured by Letters Patent of the United States is: 
     
       1. A conductor bar for a stator winding of an electrical machine, wherein said conductor bar contains edges and two bar narrow sides, said conductor bar comprising: common main insulation;   an electrically semiconductive filling material compound;   an electrically semiconductive strip, wherein said electrically semiconductive strip is composed of fiber-reinforced plastic having incisions on alternate sides of a winding overhang section of said conductor bar, said electrically semiconductive strip has outer edges, said incisions are oriented transversely with respect to said conductor bar's longitudinal direction, said incisions being deeper than half of a width of said electrically semiconductive strip and having a cut width which is of the same order of magnitude as the thickness of said electrically semiconductive strip, and said width of said electrically semiconductive strip is 1 to 4 mm smaller than a width of said conductor bar; and   a plurality of spaced apart conductor elements, wherein said plurality of spaced apart conductor elements are electrically insulated from one another and surrounded over their entire length by said common main insulation, and wherein spaces between said plurality of spaced apart conductor elements and said common main insulation are filled by said electrically semiconductive filling material compound;   wherein said outer edges of said conductor bar are rounded and said edges of said conductor bar have radii between 2 and 3 mm.   
     
     
       2. The conductor bar in claim 1, wherein edges of said electrically semiconductive filling material compound beneath said electrically conductive strip are rounded. 
     
     
       3. The conductor bar in claim 1, wherein said electrically semiconductive strip is designed in a plurality of parts, and, in a highly curved section of said conductor bar, comprises: a molding which is roughly matched to said highly curved section of said conductor bar.   
     
     
       4. The conductor bar claim 1, wherein the depth of the incisions is between 60 and 80% of the strip width, and the distance between two adjacent incisions on one side is between 10 and 20 mm. 
     
     
       5. The conductor bar in claim 3, wherein the depth of the incisions is between 60 and 80% of the strip width, and the distance between two adjacent incisions on one side is between 10 and 20 mm.